1. Field of the Invention
The present invention relates to a medical instrument provided with image pickup means for observing inside of a patient's body.
2. Description of the Related Art
As is well known, endoscope apparatuses, which are medical instruments, are provided with an image pickup apparatus, which is image pickup means, designed to be introduced into a body cavity of a patient and perform various types of inspections and treatments of affected areas in the body based on observed images taken by the image pickup apparatus. Examples of such endoscopes include those introduced into digestive organs such as esophagus, stomach, large intestine and duodenum, which are tube cavities and tubes in the body, from the oral cavity or anus and those introduced into the abdominal cavity from the vicinity of the umbilical region by puncturing through the body wall.
Endoscope apparatuses for medical care are used in such an environment that contamination such as mucous membranes, waste or blood in the body is stuck to the observation window of the image pickup apparatus or vapor is stuck to the observation window of the image pickup apparatus in a humid environment in the body causing fogging of the observation window, and these deposits may thereby impair visibility, preventing clear images from being taken. Thus, conventionally, various proposals to remove deposits stuck to the observation window of image pickup apparatuses have been presented.
For example, Japanese Patent Application Laid-Open Publication No. 8-29699 discloses an image scope provided with a wiper for wiping contamination on the outer surface of an objective lens. Furthermore, for example, Japanese Patent Application Laid-Open Publication No. 5-103748 discloses a catheter apparatus for an endoscope provided with a catheter body into which an endoscope is inserted whose observation window and channel opening portion are exposed at a distal end portion.
Techniques of conventional catheter apparatuses for an endoscope are disclosed which form a shielding member that shields at least part of an opening portion or the like of a channel at a distal end portion of the endoscope at the distal end portion of the catheter body and are also provided with a lock mechanism as suppressing means for suppressing relative rotation between the endoscope and the catheter body and capable of opening/closing the channel opening portion as required. Furthermore, a wiping member such as a buff is provided on the back of the shielding member and the wiping member is configured to be able to remove contamination or the like stuck to the observation window and illumination window of the endoscope.